Self-sealing container



y 4, 1963 H. D. SWARTZ SELF-SEALING CONTAINER 2 Sheets-Sheet 1 FiledFeb. 1, 1952 INVENTOR HENRY D. SWARTZ W014? QM FIG. 2

ATTORNEYS May 14, 1963 H. D. SWARTZ SELF-SEALING CONTAINER 2Sheets-Sheet 2 Filed Feb. 1, 1952 FIG. 4

FIG. 3

' F I 6. IO

INVENTOR.

D4 SWARTZ HENRY ATTORNEYS 3,089,636 fiELF-SEALKNG CGNTAENER Henry D.Swartz, Brooisline, Mass, assignor to Thermo= plastic Industries, Inc.,Dorchester, Mass, a corporation of Massachusetts Filed Feb. 1, H62, Ser.No. 17%,473 Qlaims. (Cl. 229--62.5)

This invention relates in general to valve bags and similar self-sealingflexible and semi-rigid containers and more particularly concerns a newand improved container which is loaded through a self-sealing tubularvalve element in communication with the interior of the container and anopening formed in a side wall of the container apart from any joint orscam.

I am aware that there are a number of commercially available valve bagswhich are loaded through a selfsealing valve having an opening locateddiagonally across a corner, or along an edge, seam or other joint of thebag. Such bags are normally filled by automatic or semiautomatic packingmachines having tubular nozzles of various diameters and lengths thatare inserted in the bag through the valve. The filling material, whetherit is a liquid, powder or granular particles, for example, is forcedrapidly into the bag until filled and the pressure of the fill againstthe valve automatically closes the valve when the nozzle and bag areseparated.

In practice, the most troublesome problem associated with this type ofbag is cracking and tearing of the bag along the seam at the valveopening. Since this part of the valve supports a substantial portion ofthe weight of the bag during the loading operation, it is subjected torather high stresses and the seams at the opening frequently split sothat the bag is no longer usable.

Accordingly, it is a general object of the present invention to providea self-sealing valve for flexible or semi-rigid containers of improvedconstruction and design.

Another object of this invention is to provide for use with flexible andsemi-rigid containers an efiicient valve element which is capable ofwithstanding considerable strain about its opening without tearing orcracking.

A more specific object of this invention is to provide a flexible,heat-scalable plastic valve bag characterized by a self-sealing valveelement which may be readily opened for filling and which is capable ofwithstanding a considerable amount of strain without ripping, tearing orotherwise failing during or after the filling operation or in transit.

More particularly, this invention features a flexible or semi-rigidcontainer having an opening formed through an outer wall or panelinwardly from the marginal edges of the wall or panel and spaced fromthe seams formed between adjacent panels. The opening is in registerwith and sealed to an opening formed in the wall of a flexible sleevewhich communicates with the interior of the con tainer and whichcollapses or folds against the opening in a self-sealing fashion underthe pressure of fill. Filling is thus accomplished through the side orwall of the container rather than through a seamed edge which isstructurally a weak area.

As another feature of this invention, the valve month has a uniqueconfiguration which permits convenient fitting of the bag onto thenozzle of a loading machine and which is adapted to support the weightof the loaded bag without tearing.

Still another feature of this invention relates to the generalconstruction of the bag which permits the use of low cost sheet materialexclusively throughout the bag and including the valve element.

But these and other features of the invention, along with furtherobjects and advantages thereof, will become more readily apparent fromthe following detailed description taken in connection with theaccompanying drawings in which:

FIG. 1 is a view in side elevation of a valve bag made according to theinvention,

FIG. 2 is a detail view, somewhat enlarged, of the valve element in theFIG. 1 device,

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 2,

1G. 4 is a view similar to FIG. 3 but showing the bag in a loadedcondition,

FIG. 5 is a view similar to FIG. 2 but showing the valve in a folded andclosed position,

FIG. 6 is a view in side elevation of the FIG. 1 valve bag attached toan automatic packing machine for fill- FIG. 7 is a view in sideelevation of a modification of the invention,

FIG. 8 is a view in perspective of a partly assembled modification ofthe invention,

FIG. 9 is a view similar to FIG. 8 but showing the completed container,and,

FIG. 10 is a view in perspective of still another modification of theinvention.

Referring now .to the drawings and more particularly.

to FIGS. 16, the reference character 10 generally indicates a valve bagfabricated from a flexible sheet material and preferably from a film oftough, flexible, heatsealable plastic material such as polyethylene orthe like. The bag 10 comprises a pair of generally rectangular panelswhich for purposes of this description may be identified as a frontpanel 12 and a rear panel 14. These panels are attached to one anotherby means of a continuous, flat, marginal seal 16 of sufiicient width tohold the panels firmly together even under high internal pressures.

At the upper right hand corner of the bag 10 there is located aself-sealing valve 18 through which the bag may be loaded with apourable fill such as liquid, powder or granular material. The valve 18is characterized by a sleeve element 20 formed from a single sheet offlexible material and preferably of the same heat seal-able polyethylenefilm of which the panels 12 and 14 are fabricated. The sleeve element 10is formed from a single rectangular panel folded back upon itself withthe free ends sealed along the upper edge of the bag and between theupper margins of the panels 12 and 14, andone end sealed along the sideedge of the bag. The opposite end of the sleeve is open at 22 so thatthe sleeve defines a passage between the interior and exterior of thebag through an opening 24 formed through the face of the panel 12 andthrough one side of the sleeve 22.

A flat seal 26, originating at the side margin of the bag, secures aportion of the lower edge of the sleeve 20 to the inner face of thefront panel 12 and extends diagonally to the upper left hand corner ofthe sleeve at the upper margin of the bag. This seal has the function ofgenerally positioning the sleeve 20 in a straight condition and againstthe side of the bag having the opening.

In a typical power bag packer such as illustrated in FIG. 6, a feed unit28 discharges a flow of fill out through a horizontal, tubular nozzle 30which is inserted through the opening 24 in the side of the bag 10. Asthe level of the fill reaches a certain predetermined height or theweight of the fill reaches a certain measure, the packer is stopped andthe bag withdrawn. It will be understood that if the level of the fillreaches the valve area, the walls of the sleeve 20 will collapse andcover the opening 24 as Patented May 14, 1963' in FIG. 4, therebysealing the bag effectively and automatically. The pressure of the fillmay not only collapse the sleeve in the manner shown in FIG. 4 but alsomay fold the free open end of the sleeve back upon itself as in FIG. 5or it may tuck into itself. In either of the latter two events, the seal26 serves to keep the sleeve from becoming displaced and also obviatesany chance of the sleeve being forced out through the opening 24.

In the preferred embodiment of the invention, the opening 24 roughlyresembles the figure 8 to afford a hand grip for easy one hand mountingto the packer. As shown, the opening has enlarged upper and lowerportions 32 and 34 connected by a restricted center portion 36 whichform opposing tabs 33 and 49. The marginal edges of the opening 24 aresealed by a continuous flat seal 42 to the sleeve 20 and to areinforcing ply 44 which may be included for added strength if desiredand which also may be of polyethylene.

The sleeve arrangement at the location of the valve opening togetherwith its unique configuration provides a number of distinct advantagesnot heretofore available in this type of bag. First of all, by locatingthe valve opening in the side of the bag rather than along an edge, asis presently the practice, the tearing and cracking of the sealed,stitched or glued seams, as frequently takes place on either side of theedge opening during filling, is eliminated. The shape of the opening issuch that it will fit snugly about a loading nozzle having effectivelythe same diameter so that Whatever stress develops between the nozzleand bag because of the weight of the fill will be distributed evenlyabout the marginal edges of the valve opening.

The tabs 38 and 40 may be readily grasped by the operator to open itsvalve mouth for filling. Also the construction permits the use of sheetmaterial throughout the bag as Well as extruded tubing or preformedsealed or glued tubes normally employed in bags of this type. When usingpreformed tubular material for the bag, it will be understood that avalve element must first be inserted and mounted before the ends of thebag are sealed. Furthermore, the side opening forms a more effectiveseal with the sleeve than is the case where the opening is at the edgeof the bag and at the end of the tubular component. In the valve of thepresent invention, it will be appreciated that the greater the innerpressure is against the sleeve the more tightly will the sleeve closeagainst the opening without stress to the seams. The action of theflattened sleeve pressed across the opening 24 by the fill forms anextremely eflicient closure for the bag such that the loaded bag may bemoved about in any position or even dropped without the loss of itscontents through leakage.

While the illustrations show the valve located near a corner of the bag,it will be appreciated that it may be arranged anywhere within themargins of the panels 12 and 14. If the valve is moved towards thecenter of a panel as suggested in FIGS. 8 and 9, a sleeve 50 formed byfolding and sealing a section of sheet material, may have one sidebonded to the inner face of a panel 52 by a flat seal 54 which extendsalong the folded edge of the section and diagonally across an end. Theloose flap that is formed may then be sealed in face to face relationwith the bonded side by a marginal flat seal 56 as shown in FIG. 9. Inthe FIGS. 8 and 9 embodiment, a circular opening 58 is formed throughthe panel 52 and one side of the sleeve 50. As before, the opening maybe reinforced by a ply 60 and the edges of the three plies bondedtogether by a continuous flat seal 62. It will be noted that the sleeve50 has a tapered configuration so as to reduce the size of the sleeveopening 64 and thereby further enhance the sealing characteristics ofthe valve.

It will be understood also that the valve opening 24 in the FIG. 1embodiment may be disposed angularly with respect to the sides of thebag rather than being formed 4 in the position shown. Likewise the flatseal 26 for bonding the sleeve to the panel 12 may be arranged in avariety of different ways.

In FIG. 7 there is illustrated a valve opening 70 and valve sleeve 72located in a neck portion 74 of a flexible valve bag 76 which may befabricated from a heat sealable plastic film such as polyethylene forexample. As in the FIG. 8 embodiment, the sleeve 72 is bonded to theinner surface of one of the bag panels.

In FIG. 10 a valve 8% similar to that shown and described in referenceto the FIG. 7 embodiment, is employed in a semi-rigid, three-dimensionalcontainer 82 extruded, molded or otherwise formed from a relativelystiff material that is preferably a heat scalable plastic composition.As in the previous embodiments, the valve is located in the side of thecontainer apart from any seam or joint which might crack or weaken understress.

For liquid handling purposes, it has been found that a tighter, moreefiicient seal is obtained if the valve opening is made relatively smallin relation to the size of the bag. For packing powder and granularmaterial a relatively large opening functions efficiently. In order toprevent billowing of the bag, several pinholes 84 (FIG. 1) may be madein the panels 12 and 14. These pinholes allow excess air to escape fromthe bag but should not be provided where the bag is to be filled withliquid.

While the invention has been described with particular reference to theillustrated embodiments, it will be understood that numerousmodifications will appear to those skilled in the art without departingfrom the spirit of my invention. For example, a variety of materials maybe used to fabricate valve bags of the type described. A polyethylenecoated paper may be used to advantage because of its strength and heatscalability characteristics. Various other sheet materials may also beused. Furthermore, the several components may be bonded into properrelation by cementing rather than by a heat sealing process. Thecontainer may, of course, be made in any desired configuration, such ascircular or spherical, for example and the illustrated embodiments areto be taken in an illustrative rather than in a limiting sense.

Having thus described my invention, what I claim and desire to obtain byLetters Patent of the United States is:

1. A flexible valve bag, comprising a plurality of panels marginallyattached to one another to form a bag, said panels being fabricated froma flexible material, at least one of said panels being formed with anopening therethrough, said opening being located within the margins ofsaid one panel, a flexible sleeve disposed within said bag, said sleevebeing closed at one end and open at an opposite end, one side of saidsleeve being attached to the inner face of the panel in which is formedthe opening, said one side of said sleeve being attached to said panelalong a generally transverse line being located generally midway betweenthe ends of said sleeve to define a foldable flap at the free end ofsaid sleeve, said sleeve being formed with an opening through said oneside, said sleeve opening being in register with said panel opening andthe marginal edges of both of said openings being bonded to one another.

2. A flexible valve bag according to claim 1 wherein said panels andsaid sleeve are fabricated at least in part from a material thatpossesses heat sealing characteristics.

3. A flexible valve bag according to claim 2 wherein said material ispolyethylene.

4. A flexible valve bag according to claim 1 wherein the marginal edgesdefining said opening include a pair of arcuate segments joined by atleast one segment of reversed curvature to define a tab whereby accessto said opening is facilitated.

5. A flexible valve bag, comprising a tube of flexible material, saidtube being closed at both ends to form a bag, said tube being formedwith an opening through a wall thereof, a flexible sleeve disposedwithin said bag, said sleeve being closed at one end and open at anopposite end, one side of said sleeve being attached to the inner faceof the tube wall in which is formed the openings said one side of saidsleeve being attached to said tube Wall along a line extendinglengthwise of said sleeve adjacent a portion of long side thereof andextending diagonally across the mid portion thereof to define a foldableflap at the free end of said sleeve, said sleeve being formed with anopening through said one side, said sleeve opening being in registerwith said tube wall opening and the marginal edges of both of saidopenings being bonded to one another.

References Cited in the file of this patent UNITED STATES PATENTS

1. A FLEXIBLE VALVE BAG, COMPRISING A PLURALITY OF PANELS MARGINALLYATTACHED TO ONE ANOTHER TO FORM A BAG, SAID PANELS BEING FABRICATED FROMA FLEXIBLE MATERIAL, AT LEAST ONE OF SAID PANELS BEING FORMED WITH ANOPENING THERETHROUGH, SAID OPENING BEING LOCATED WITHIN THE MARGINS OFSAID ONE PANEL, A FLEXIBLE SLEEVE DISPOSED WITHIN SAID BAG, SAID SLEEVEBEING CLOSED AT ONE END AND OPEN AT AN OPPOSITE END, ONE SIDE OF SAIDSLEEVE BEING ATTACHED TO THE INNER FACE OF THE PANEL IN WHICH IS FORMEDTHE OPENINGS, SAID ONE SIDE OF SAID SLEEVE BEING ATTACHED TO SAID PANELALONG A GENERALLY TRANSVERSE LINE BEING LOCATED GENERALLY MIDWAY BETWEENTHE ENDS OF SAID SLEEVE TO DEFINE A FOLDABLE FLAP AT THE FREE END OFSAID SLEEVE, SAID SLEEVE BEING FORMED WITH AN OPENING THROUGH SAID ONESIDE, SAID SLEEVE OPENING BEING IN REGISTER WITH SAID PANEL OPENING ANDTHE MARGINAL EDGES OF BOTH OF SAID OPENINGS BEING BONDED TO ONE ANOTHER.